Septacidin (IV) is an antitumor antibiotic in which the sugar moiety is a 4-amino-deoxy-L-heptose. The first totally synthetic analogs to be produced will be those having changes in the substituent (R) at carbon-5 of the sugar. In the second year of this work, synthesis of the first analog (II) will be completed by attachment of the isopalmitoylglycyl side chain to the already synthesized aminonucleoside of II. Using the synthetic approach devised for II, but using L-galactose as the starting sugar, we will synthesize the second analog (III), which will have 4-amino-4-deoxy-L-glucose as the sugar component. Properties of III will be compared with those of a septacidin degradation product assigned the same structure. The first total synthesis of septacidin (IV) similarly will be undertaken starting from L-galactose; a chain-extension step will be included in the process to provide the heptose moeity. This step undoubtedly will also yeild the epimer V as a potentially interesting by-product. Synthesis of the pentose analog (I) also will be undertaken, with D-arabinose as starting sugar in the same synthetic approach. Targets will be tested for antitumor properties and cytotoxicity.